Love this idea! (I often see similar activities for math, but this is the first time I've seen this activity used within a literacy lesson.) This could be a great exit ticket idea for the topic they just learned about.
I love colorful displays, so this crayon classroom door display "Get Ready for a COLORFUL YEAR! OUR NEW PACK" is an idea I'd love to use. This idea would also look great as a Back to School bulletin board display. Put all the kids names up to be a crayon.